<atPopover [placement]="'top'">
  <button atButton popTrigger>
    hello
  </button>
  <div popContent>
    你好吗？
  </div>
</atPopover>


<atPopover [placement]="'top'" [trigger]="'hover'">
  <button atButton popTrigger>
    hello
  </button>
  <div popContent>
    你好吗？
  </div>
</atPopover>
